U.S. patent application number 12/022143 was filed with the patent office on 2008-07-31 for concrete reinforcement support chair.
Invention is credited to Gary Dan McKay.
Application Number | 20080178554 12/022143 |
Document ID | / |
Family ID | 39666376 |
Filed Date | 2008-07-31 |
United States Patent
Application |
20080178554 |
Kind Code |
A1 |
McKay; Gary Dan |
July 31, 2008 |
Concrete Reinforcement Support Chair
Abstract
An apparatus ("chair") for supporting one or more reinforcement
bars or post-tension cables ("bars/cables") in a concrete structure
includes a base member having a centered opening, a pair of
opposing first leg members extending upward from the base member at
a first angle, a pair of opposing second leg members extending
upward from the base member at a second angle, and a strap-shaped
locking cradle. The strap-shaped locking cradle includes an
arc-shaped receiving portion attached to the first and second leg
members, a flexible portion suitable for wrapping over the
bars/cables and a fastener to affix the flexible portion to the
arc-shaped receiving portion or one of the first leg members such
that transverse and vertical movement of the bars/cables is limited
and longitudinal movement of the bars/cables is allowed.
Inventors: |
McKay; Gary Dan; (Frisco,
TX) |
Correspondence
Address: |
CHALKER FLORES, LLP
2711 LBJ FRWY, Suite 1036
DALLAS
TX
75234
US
|
Family ID: |
39666376 |
Appl. No.: |
12/022143 |
Filed: |
January 29, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60887080 |
Jan 29, 2007 |
|
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Current U.S.
Class: |
52/685 ;
52/309.1; 52/379 |
Current CPC
Class: |
E04C 5/20 20130101 |
Class at
Publication: |
52/685 ;
52/309.1; 52/379 |
International
Class: |
E04C 5/16 20060101
E04C005/16 |
Claims
1. An apparatus for supporting one or more reinforcement bars or
post-tension cables ("bars/cables") in a concrete structure, the
apparatus comprising: a base member having a centered opening; a
pair of opposing first leg members extending upward from the base
member at a first angle; a pair of opposing second leg members
extending upward from the base member at a second angle; and a
strap-shaped locking cradle comprising an arc-shaped receiving
portion attached to the first and second leg members, a flexible
portion suitable for wrapping over the bars/cables and a fastener
to affix the flexible portion to the arc-shaped receiving portion
or one of the first leg members such that transverse and vertical
movement of the bars/cables is limited and longitudinal movement of
the bars/cables is allowed.
2. The apparatus as recited in claim 1 further comprising a spike
extending downward from the strap-shaped locking cradle through the
centered opening.
3. The apparatus as recited in claim 1 wherein the transverse and
vertical movement of the bars/cables is prevented.
4. The apparatus as recited in claim 1 wherein: the first and
second angle are the same or the first and second angle are
different; the first leg members are oriented perpendicular to the
longitudinal axis of the bars/cables; and the second leg members
are oriented with a longitudinal axis of the bars/cables.
5. The apparatus as recited in claim 1 wherein the fastener
comprises a slotted tab and hook fastener, a hook and notch
fastener, a tap and notch fastener, a loop and hook fastener or a
reusable snap-type fastener.
6. The apparatus as recited in claim 1 wherein the fastener is
adjustable to accommodate different sized bars/cables.
7. The apparatus as recited in claim 1 wherein the fastener can be
opened and closed without damaging the fastener.
8. The apparatus as recited in claim 2 wherein the spike has one or
more break point notches between the strap-shaped locking cradle
and the centered opening that allow the spike to be broken off at
or above the base member.
9. The apparatus as recited in claim 2 wherein the spike extends at
least one inch below the base member and the spike is integrated
into the second pair of leg members.
10. The apparatus as recited in claim 1 wherein: the base member is
circular, round, oval, elliptical, triangular, rectangular,
hexagonal or other polygonal shape; and the first and second leg
members are I-beam shaped, circular, square or triangular.
11. The apparatus as recited in claim 1 wherein the base member is
substantially flat or rounded.
12. The apparatus as recited in claim 2 wherein: the spike is
I-beam shaped, circular, square or triangular; and the spike has a
tip that is pointed or arrow-shaped.
13. The apparatus as recited in claim 1 wherein the strap-shaped
locking cradle supports two or more parallel bars/cables.
14. The apparatus as recited in claim 1 wherein the apparatus is
manufactured using a mold injection process.
15. The apparatus as recited in claim 1 wherein the apparatus is
formed of a material selected from the group consisting of nylon,
polypropylene, polyethylene and moldable composites.
16. An apparatus for supporting one or more reinforcement bars or
post-tension cables ("bars/cables") in a concrete structure, the
apparatus comprising: a base member having a centered opening; a
pair of opposing first leg members extending upward from the base
member at a first angle oriented perpendicular to the longitudinal
axis of the bars/cables; a pair of opposing second leg members
extending upward from the base member at a second angle oriented
with a longitudinal axis of the bars/cables; a strap-shaped locking
cradle comprising an arc-shaped receiving portion attached to the
first and second leg members, a flexible portion suitable for
wrapping over the bars/cables and a fastener to affix the flexible
portion to the arc-shaped receiving portion or one of the first leg
members such that transverse and vertical movement of the
bars/cables is limited and longitudinal movement of the bars/cables
is allowed, and wherein the fastener can be opened and closed
without damaging the fastener; and a spike extending downward from
the strap-shaped locking cradle through the centered opening to at
least one inch below the based member, wherein the spike has one or
more break point notches between the strap-shaped locking cradle
and the centered opening that allow the spike to be broken off at
or above the base member.
17. The apparatus as recited in claim 16 wherein the fastener
comprises a slotted tab and hook fastener, a hook and notch
fastener, a tap and notch fastener, a loop and hook fastener or a
reusable snap-type fastener, and the fastener is adjustable to
accommodate different sized bars/cables.
18. An apparatus for supporting one or more reinforcement bars or
post-tension cables ("bars/cables") in a concrete structure, the
apparatus comprising: a substantially flat base member having a
centered opening; a pair of opposing first I-beam shaped leg
members extending upward from the base member at a first angle
oriented perpendicular to the longitudinal axis of the bars/cables;
a pair of opposing second I-beam shaped leg members extending
upward from the base member at a second angle oriented with a
longitudinal axis of the bars/cables; a strap-shaped locking cradle
comprising an arc-shaped receiving portion attached to the first
and second leg members, a flexible portion suitable for wrapping
over the bars/cables and a fastener to affix the flexible portion
to the arc-shaped receiving portion or one of the first leg members
such that transverse and vertical movement of the bars/cables is
limited and longitudinal movement of the bars/cables is allowed,
and wherein the fastener can be opened and closed without damaging
the fastener; and an I-beam shaped spike extending downward from
the strap-shaped locking cradle through the centered opening to at
least one inch below the based member, wherein the spike has one or
more break point notches between the strap-shaped locking cradle
and the centered opening that allow the spike to be broken off at
or above the base member.
19. The apparatus as recited in claim 18 wherein the fastener
comprises a slotted tab and hook fastener, a hook and notch
fastener, a tap and notch fastener, a loop and hook fastener or a
reusable snap-type fastener, and the fastener is adjustable to
accommodate different sized bars/cables.
20. A concrete structure comprising: a lattice of reinforcement
bars or post-tension cables ("bars/cables"); a set of chairs
supporting the lattice of bars/cables, wherein each chair comprises
a base member having a centered opening, a pair of opposing first
leg members extending upward from the base member at a first angle,
a pair of opposing second leg members extending upward from the
base member at a second angle, and a strap-shaped locking cradle
comprising an arc-shaped receiving portion attached to the first
and second leg members, a flexible portion suitable for wrapping
over the bars/cables and a fastener to affix the flexible portion
to the arc-shaped receiving portion or one of the first leg members
such that transverse and vertical movement of the bars/cables is
limited and longitudinal movement of the bars/cables is allowed;
and concrete substantially encapsulating the lattice of bars/cables
and the set of chairs.
Description
PRIORITY CLAIM AND CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a non-provisional application of
U.S. provisional patent application Ser. No. 60/887,080 filed on
Jan. 29, 2007 and entitled "Concrete Reinforcement Support Chair"
which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of
construction and, more particularly, to a concrete reinforcement
support chair.
BACKGROUND OF THE INVENTION
[0003] The main function of concrete reinforcement support chairs,
commonly referred to as chairs, is to hold tension cables and
reinforcement bars/rods ("rebar") within concrete structures, such
as roadways, highways, runways, floors, building walls, retaining
walls, foundations and flat work. Wire ties have long been used to
connect the chairs to the cables or rebar. Extra labor time and
expense is necessary to install the ties by hand. In addition,
chairs are often overlooked or skipped during the tying
process.
[0004] More recently, chairs have been developed that do not
require the use of separate ties, but such chairs are securely
affixed to the cables or rebar. As a result, these chairs are
susceptible to movement when the cables or rebar are being laid or
tensioned, or when the concrete is poured. The resulting movement
can affect the structural integrity of the concrete structure.
Moreover, these chairs do not allow for opening or reclosing the
fasteners without great difficulty or a high probability of damage
to the chair. As a result, such chairs do not allow for relocation
or adjustment. Moreover, some of these chairs also have multiple
parts that increase the complexity and cost of the
installation.
[0005] Another problem occurs when liquid concrete flows into a
form. The force of the concrete displaces plastic chair supports
out of position to float freely within the concrete matrix, or
causes them to rotate around and upward on the cable, leaving them
sticking out of the finished concrete. When the flow of concrete
knocks over chairs which are tied to cables, the cables are
stretched and pushed out of the engineered pattern. Yet another
problem occurs when moisture barriers of polyurethane, or similar
materials, are installed beneath concrete. In such installations,
there is a tendency for the sheets of barrier material to blowout
of place in windy conditions. This can also cause movement or
rotation of the chairs. Additionally, air pockets occur between the
ground and the barrier material when concrete is poured into place,
creating thin, weakened areas of concrete which cause potential
structural problems. Although some chairs have been designed with
small projections on the feet/base to increase friction, such
projections are not long enough to adequately solve these problems.
Moreover, the installer must select chairs with projections or
without projections--the chairs are not configurable in the
field.
[0006] As a result, there is a need for a chair that is inexpensive
to manufacture, easy to install and allows for longitudinal
movement of the cables or bars.
SUMMARY OF THE INVENTION
[0007] The present invention provides a chair that is inexpensive
to manufacture, easy to install and allows for longitudinal
movement of the cables or bars. The present invention provides a
one-piece mold-injected concrete reinforcement support chair is
made of plastic-type materials and designed to support concrete
reinforcement materials within the middle of a concrete slab. In
various embodiments, the present invention provides a top-over
slotted tab and hook fastener and/or a snap-off spike. These
features, when combined with each other and with other improved
design changes in the body of the chair, address problems
encountered with use of currently marketed chairs and problems that
have come about in recent years with increased use of post-tension
cable systems in concrete foundations. The present invention can
also be used within many concrete structures, such as roadways,
highways, runways, floors, building walls, retaining walls,
foundations and flat work.
[0008] In one embodiment, the present invention provides an
apparatus ("chair") for supporting one or more reinforcement bars
or post-tension cables ("bars/cables") in a concrete structure. The
apparatus includes a base member having a centered opening, a pair
of opposing first leg members extending upward from the base member
at a first angle, a pair of opposing second leg members extending
upward from the base member at a second angle, and a strap-shaped
locking cradle. The strap-shaped locking cradle includes an
arc-shaped receiving portion attached to the first and second leg
members, a flexible portion suitable for wrapping over the
bars/cables and a fastener to affix the flexible portion to the
arc-shaped receiving portion or one of the first leg members such
that transverse and vertical movement of the bars/cables is limited
and longitudinal movement of the bars/cables is allowed.
[0009] In another embodiment, the present invention provides a
chair for supporting one or more bars/cables in a concrete
structure. The chair includes a base member having a centered
opening, a pair of opposing first leg members extending upward from
the base member at a first angle oriented perpendicular to the
longitudinal axis of the bars/cables, a pair of opposing second leg
members extending upward from the base member at a second angle
oriented with a longitudinal axis of the bars/cables, a
strap-shaped locking cradle and a spike. The strap-shaped locking
cradle includes an arc-shaped receiving portion attached to the
first and second leg members, a flexible portion suitable for
wrapping over the bars/cables and a fastener to affix the flexible
portion to the arc-shaped receiving portion or one of the first leg
members such that transverse and vertical movement of the
bars/cables is limited and longitudinal movement of the bars/cables
is allowed, and wherein the fastener can be opened and closed
without damaging the fastener. The spike extends downward from the
strap-shaped locking cradle through the centered opening to at
least one inch below the based member, wherein the spike has one or
more break point notches between the strap-shaped locking cradle
and the centered opening that allow the spike to be broken off at
or above the base member.
[0010] In yet another embodiment, the present invention provides a
chair for supporting one or more bars/cables in a concrete
structure. The chair includes a substantially flat base member
having a centered opening, a pair of opposing first I-beam shaped
leg members extending upward from the base member at a first angle
oriented perpendicular to the longitudinal axis of the bars/cables,
a pair of opposing second I-beam shaped leg members extending
upward from the base member at a second angle oriented with a
longitudinal axis of the bars/cables, a strap-shaped locking cradle
and an I-beam shaped spike. The strap-shaped locking cradle
includes an arc-shaped receiving portion attached to the first and
second leg members, a flexible portion suitable for wrapping over
the bars/cables and a fastener to affix the flexible portion to the
arc-shaped receiving portion or one of the first leg members such
that transverse and vertical movement of the bars/cables is limited
and longitudinal movement of the bars/cables is allowed, and
wherein the fastener can be opened and closed without damaging the
fastener. The I-beam shaped spike extends downward from the
strap-shaped locking cradle through the centered opening to at
least one inch below the based member, wherein the spike has one or
more break point notches between the strap-shaped locking cradle
and the centered opening that allow the spike to be broken off at
or above the base member.
[0011] Another embodiment of the present invention provides a
concrete structure, such as a roadway, highway, runway, floor,
building wall, retaining wall, foundation or flat work, that
includes a lattice of reinforcement bars or post-tension cables, a
set of chairs supporting the lattice of bars/cables, and concrete
substantially encapsulating the lattice of bars/cables and the set
of chairs. Each chair includes a base member having a centered
opening, a pair of opposing first leg members extending upward from
the base member at a first angle, a pair of opposing second leg
members extending upward from the base member at a second angle,
and a strap-shaped locking cradle comprising an arc-shaped
receiving portion attached to the first and second leg members, a
flexible portion suitable for wrapping over the bars/cables and a
fastener to affix the flexible portion to the arc-shaped receiving
portion or one of the first leg members such that transverse and
vertical movement of the bars/cables is limited and longitudinal
movement of the bars/cables is allowed.
[0012] The present invention is described in detail below with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and further advantages of the invention may be
better understood by referring to the following description in
conjunction with the accompanying drawings, in which:
[0014] FIG. 1 is a isometric view of a chair in accordance with one
embodiment of the present invention;
[0015] FIG. 2 is a side view of the chair shown in FIG. 1;
[0016] FIG. 3 is a top view of the chair shown in FIG. 1;
[0017] FIG. 4 is an illustration of a chair in accordance with one
embodiment of the present invention connected to a cable; and
[0018] FIG. 5 is an illustration of a chair in accordance with one
embodiment of the present invention connected to a rebar.
DETAILED DESCRIPTION OF THE INVENTION
[0019] While the making and using of various embodiments of the
present invention are discussed in detail below, it should be
appreciated that the present invention provides many applicable
inventive concepts that can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative of specific ways to make and use the invention
and do not delimit the scope of the invention.
[0020] The present invention provides a chair that is inexpensive
to manufacture, easy to install and allows for longitudinal
movement of the cables or bars. The present invention provides a
one-piece mold-injected concrete reinforcement support chair is
made of plastic-type materials and designed to support concrete
reinforcement materials within the middle of a concrete slab. In
various embodiments, the present invention provides a top-over
slotted tab and hook fastener and/or a snap-off spike. These
features, when combined with each other and with other improved
design changes in the body of the chair, address problems
encountered with use of currently marketed chairs and problems that
have come about in recent years with increased use of post-tension
cable systems in concrete foundations. The present invention can
also be used within many concrete structures, such as roadways,
highways, runways, floors, building walls, retaining walls,
foundations and flat work.
[0021] Now referring to FIGS. 1, 2 and 3, various views of a chair
100 in accordance with one embodiment of the present invention are
shown. The chair 100 includes a base member 102 having a centered
opening 104, a pair of opposing first leg members 106 extending
upward from the base member 102 at a first angle 108, a pair of
opposing second leg members 110 extending upward from the base
member 102 at a second angle, and a strap-shaped locking cradle
112. The base member 102 can be circular, round, oval, elliptical,
triangular, rectangular, hexagonal or other polygonal shape.
Moreover, the base member 102 can be substantially flat or rounded.
For example, a flat, elliptically shaped base member 102, which
sits at ground level, the longer side of which runs perpendicular
to the direction of inserted post-tension cables and rebar allows
for lengthwise movement of the cables while other chairs are being
installed without disturbing the placement of other placed chairs.
The first and second leg members (106 and 110) can be I-beam
shaped, circular, square or triangular. Note that I-beam shaped leg
members (106 and 110) can be used to provide extra strength against
the force of liquid concrete. The first and second angle can be the
same or different depending on the specific size and application of
the chair. As shown, the first leg members are oriented
perpendicular to the longitudinal axis of the bars/cables; and the
second leg members are oriented with a longitudinal axis of the
bars/cables.
[0022] The strap-shaped locking cradle 112 includes an arc-shaped
receiving portion 114 attached to the first and second leg members
(106 and 110), a flexible portion 116 suitable for firmly wrapping
over the bars/cables and a fastener 118 to affix the flexible
portion 116 to the arc-shaped receiving portion 114 or one of the
first leg members 106 such that transverse and vertical movement of
the bars/cables is limited and longitudinal movement of the
bars/cables is allowed. Note that the transverse and vertical
movement of the bars/cables can also be prevented. The fastener 112
can be a slotted tab and hook fastener (shown), a hook and notch
fastener, a tap and notch fastener, a loop and hook fastener (e.g.,
Velcro.RTM.) or a reusable snap-type fastener. Moreover, the
fastener 112 can be adjustable to accommodate different sized
bars/cables. Furthermore, the fastener 112 can be opened and closed
without damaging the fastener to accommodate relocation or
adjustments to cables and rebar. The strap-shaped locking cradle
112 can support two or more parallel bars/cables.
[0023] As shown, the chair 100 also includes a spike 120 extending
downward from the strap-shaped locking cradle 112 through the
centered opening 104. The spike 120 includes one or more break
point notches 122 between the strap-shaped locking cradle 112 and
the centered opening 104 that allow the spike 120 to be broken off
at or above the base member 102 when the spike 120 is not needed or
not allowed. The spike 120 preferably extends at least one inch
below the base member 102. Other lengths can be used, such as one
and one-half inches or two inches. The spike 120 when inserted into
the ground provides give added stability to the chair's placement.
This may occur when plumbing pipes or utility lines are already
installed or when concrete will be poured over old existing
concrete, asphalt, or other previously-installed materials. The
spike 120 decreases the occurrence of cable-bowing by staking the
chairs 100 in place to the ground. The spike 120 provides the
additional benefits of holding moisture barrier materials in place,
allowing air to escape through the spike penetration hole from
between the barrier and the ground, and keeping cables in place
according to engineered plans. The spike 120 can be I-beam shaped,
circular, square or triangular. Moreover, the spike 120 can have a
tip 124 that is pointed or arrow-shaped. The spike 120 can also be
integrated into the second pair of leg members 110 such that the
second pair of leg members 110 can be thinner and do not require
the added strength of an I-beam shape (See FIGS. 4 and 5).
[0024] The chair 100 can be manufactured using a mold injection
process. Accordingly, the chair 100 can be formed of nylon,
polypropylene, polyethylene or moldable composites. Other suitable
materials may also be used. The chair 100 can be modified at the
time of manufacture for use in a thicker slab by adjusting the
total height of the chair; the length, diameter or shape of its
support legs; the capacity of the fastener; the diameter or length
of the spike; and/or the size of any of its components. The height
of the support legs and the size or capacity of the fastener can be
varied during manufacturing to accommodate variable post-tension
cable and rebar sizes. The chair 100 is best used by determining
and choosing the best size necessary as established by generally
accepted engineering principles of concrete design and
construction, inserting and locking rebar and post-tension cables
in place into the top-over slotted tab-and-hook fastener, and
inserting the spike into the ground. This will ensure both
reinforcement materials and support chair stay in place during
placement of concrete. Alternative forms of the product may be
manufactured by changing or altering individual features. For
example, the spike may be made in round cylindrical triangular
shapes. It may be made in various lengths and widths. It might be
given an arrow-shaped tip. It might be made without the snap-off
feature. The elliptical shape of the base might be changed to a
circular, round, oval, triangular, rectangular, or other
geometrical shape, but it will achieve optimal results by using the
elliptical shape as designed. The base may be changed from a flat
design to one of a more round one. The I-beam support legs may be
made in round or square shapes, without the I-beam construction.
I-beam construction gives the optimum strength and stability for
the industry in which the unit will be used. The top-over slotted
tab-and-hook fastener might be given additional stop notches and/or
holes to handle different support material sizes. The seat where
the cable and/or rebar sit can be enlarged to accommodate two
same-direction pieces of rebar as required by engineered
drawings.
[0025] Some examples of the chair 100 are shown in FIGS. 4 and 5.
FIG. 4 illustrates of a chair 100 connected to a cable. FIG. 5
illustrates of a chair 100 connected to a rebar. The other
described embodiments of the present invention are derived by using
specific design alternatives described in reference to FIGS. 1-3.
Moreover, these embodiments can be used in a concrete structure,
such as a roadway, highway, runway, floor, building wall, retaining
wall, foundation or flat work. The concrete structure includes a
lattice of reinforcement bars or post-tension cables, a set of
chairs supporting the lattice of bars/cables, and concrete
substantially encapsulating the lattice of bars/cables and the set
of chairs. Each chair includes a base member having a centered
opening, a pair of opposing first leg members extending upward from
the base member at a first angle, a pair of opposing second leg
members extending upward from the base member at a second angle,
and a strap-shaped locking cradle comprising an arc-shaped
receiving portion attached to the first and second leg members, a
flexible portion suitable for wrapping over the bars/cables and a
fastener to affix the flexible portion to the arc-shaped receiving
portion or one of the first leg members such that transverse and
vertical movement of the bars/cables is limited and longitudinal
movement of the bars/cables is allowed.
[0026] Although preferred embodiments of the present invention have
been described in detail, it will be understood by those skilled in
the art that various modifications can be made therein without
departing from the spirit and scope of the invention as set forth
in the appended claims.
* * * * *